US 10,381,992 B1Granted

Amplitude control with signal swapping

AssigneeTexas Instruments Incorporated

InventorGeorge Reitsma

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Abstract

A circuit includes a first signal swapper including a first terminal coupled to a first current source, a second terminal coupled to a second current source, a third terminal coupled to a first current terminal of a first transistor, and a fourth terminal coupled to a third current terminal of a second transistor. The first signal swapper couples the first and second terminals to the third and fourth terminals responsive to a first control signal. First and second switches couple to a gate of the first transistor. The first switch receives the input oscillation signal and the second switch receives a first reference voltage. Third and fourth switches couple to a gate of the second transistor. The third switch receives the input oscillation signal and the fourth switch receives the first reference voltage. A second signal swapper couples to the first signal swapper and to the first and second transistors.

Claims17

Dependent claims

A circuit, comprising:

a first transistor including a first control input, a first current terminal, and a second current terminal;
a second transistor including a second control input, a third current terminal, and a fourth current terminal;
a first signal swapper including a first terminal to couple to a first current source, a second terminal to couple to a second current source, a third terminal to couple to the first current terminal of the first transistor, and a fourth terminal to couple to the third current terminal of the second transistor, wherein the first signal swapper selectively electrically couples the first and second terminals to the third and fourth terminals responsive to a first control signal derived from an input oscillation signal;
first and second switches to couple to the first control input of the first transistor, the first switch coupled to receive the input oscillation signal and the second switch coupled to receive a first reference voltage;
third and fourth switches to couple to the second control input of the second transistor, the third switch coupled to receive the input oscillation signal and the fourth switch coupled to receive the first reference voltage;
a second signal swapper coupled to the first signal swapper, to the first current terminal of the first transistor and to the third current terminal of the second transistor;
a first resistor coupled to the second current terminal of the first transistor;
a second resistor coupled in series with the first resistor;
a fifth switch coupled in parallel with the second resistor;
a third resistor coupled to the fourth current terminal of the second transistor;
a fourth resistor coupled in series with the third resistor;
and
a sixth switch coupled in parallel with the fourth resistor.

10 more elements

A circuit, comprising:

a first transistor including a first control input, a first current terminal, and a second current terminal;
a second transistor including a second control input, a third current terminal, and a fourth current terminal;
a first signal swapper including a first terminal to couple to a first current source, a second terminal to couple to a second current source, a third terminal to couple to the first current terminal of the first transistor, and a fourth terminal to couple to the third current terminal of the second transistor, wherein the first signal swapper selectively electrically couples the first and second terminals to the third and fourth terminals responsive to a first control signal derived from an input oscillation signal;
first and second switches to couple to the first control input of the first transistor, the first switch coupled to receive the input oscillation signal and the second switch coupled to receive a first reference voltage;
third and fourth switches to couple to the second control input of the second transistor, the third switch coupled to receive the input oscillation signal and the fourth switch coupled to receive the first reference voltage;
a second signal swapper coupled to the first signal swapper, to the first current terminal of the first transistor and to the third current terminal of the second transistor;
a filter coupled to a third node between the first signal swapper and the second signal swapper, wherein a current from the third node to the filter has a magnitude that proportional to a difference between a current through the first transistor and a current through the second transistor.

4 more elements

A circuit, comprising:

a first rectifier coupled to rectify an input oscillation signal as a first rectified output signal;
a second rectifier coupled to rectify the input oscillation signal as a second rectified output signal;
a first analog multiplexer having a first output and configured to select, responsive to a first control signal derived from an input oscillation signal, as the first output the first rectified output signal or a reference signal;
a second analog multiplexer having a second output and configured to select, responsive to the first control signal, as the second output the other one of the second rectified output signal or the reference signal not selected by first analog multiplexer;
a first selectable gain amplifier coupled to the first analog multiplexer and configured, responsive to the first control signal, to select between a first gain or a second gain for application to the first output from the first analog multiplexer;
a second selectable gain amplifier coupled to the second analog multiplexer and configured, responsive to the first control signal, to select between the other of the first gain or the second gain not selected by the first selectable gain amplifier, for application to the second output from the second analog multiplexer;
and
a signal swapper coupled to the first and second selectable gain amplifiers and including a first signal swapper output and a second signal swapper output, wherein the signal swapper is configured to select, responsive to the first control signal, as the first signal swapper output a signal from one of the first and second gain amplifiers and as the second signal swapper output the other signal from the first and second gain amplifiers.

5 more elements

A circuit, comprising:

a first transistor including a first control input, a first current terminal, and a second current terminal;
a second transistor including a second control input, a third current terminal, and a fourth current terminal;
a first signal swapper including a first terminal to couple to a first current source terminal, a second terminal to couple to a second current source terminal, a third terminal to couple to the first current terminal of the first transistor, and a fourth terminal to couple to the third current terminal of the second transistor, wherein the first signal swapper selectively electrically couples the first and second terminals to the third and fourth terminals responsive to a first control signal derived from an input oscillation signal;
a first rectifier and a first analog multiplexer to rectify the input oscillation signal to produce a first rectified signal and to select between the first rectified signal and a first reference voltage;
a second rectifier and a second analog multiplexer to rectify the input oscillation signal to produce a second rectified signal and to select between the second rectified signal and the first reference voltage;
and
a second signal swapper coupled to the first transistor, the second transistor, and the first signal swapper, the second signal swapper to selectively couple the first transistor to one of the first and second current source terminals and to couple the second transistor to the other of the first and second current source terminals.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/899,598Filed 20 Feb 2018
Published: US 2019/0260339 A122 Aug 2019
Granted: 13 Aug 2019
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

H03F 3/45475
Characterised by the way of implementation of the active amplifying circuit in the differential amplifier: using IC blocks as the active…
H03D 7/1441
With transistors: using field-effect transistors
H03D 7/1458
With transistors: double balanced arrangements, i.e. where both input signals are differential
H03D 7/165
Multiple-frequency-changing: at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature